How to decrease the running time of a macro? (VBA)

Turning off the screen updating is one of the best ways to decrease the running time of a macro and it is also very easy to use, just assign it to False at the beginning of your macro and to True at the end, as shown on the example:

Sub my_macro()

Application.ScreenUpdating = False

 'write here the code

Application.ScreenUpdating = True

End Sub